Someone that truly feels well, doesn't eat themselves until they vomit, or drink themselves into a stupor. Someone truly healthy has a mind that functions well, a body that functions well, and an emotional understanding that functions well, to maintain a high quality of life - not a good feeling right now, at the expense of everything else to come.
That's the whole point. Excess food is stored as fat in the body. It's a burden, a weight we have to carry. It's foolish. I could understand this if we were bears; we are a people with so much potential and variety. Living for the day might make sense in some circumstances, but it will cost us greatly in the future. Eat a healthy, balanced, and regular diet. Get 6-7 hours of sleep. Exercise regularly. Actually, what we need to do is very difficult. It's not.